This invention is directed to clutch and drive train systems for vehicles and more particularly to a bleeding tool and method to remove entrapped air from the clutch hydraulic control assembly of a clutch type transmission.
A closed hydraulic system depends on a continuous flow of a hydraulic fluid to operate properly. Any air trapped in the system will cause the different components to not transmit the correct hydraulic pressures from place to place in the system. The air becomes a compressible fluid where the hydraulic fluid is incompressible. The clutch hydraulic control assembly of a vehicle can get air trapped in the system from time to time. The general use of hydraulic cylinders to transmit fluid pressures into movements of a push rod are components that can allow air into the fluid system. The seals around the push rods become worn and leak. The clutch hydraulic control assembly generally includes a hydraulic fluid reservoir. If the fluid level in this reservoir is not maintained above a certain level, air is again introduced into the assembly. Components are generally connected by hydraulic lines which can develop a leak in the line or in the connections between the lines and the components they interconnect.
Generally speaking, to remove air trapped in a closed hydraulic system is a difficult task. Air bubbles and pockets of air in the closed hydraulic system are difficult to remove. The clutch hydraulic control assembly of a vehicle is no exception. The removal procedure is similar to bleeding a brake system, but depends on gravity for the bleeding effect. Repair manuals supplied by the manufacturers generally state that “the hydraulic system should be bled to remove all air whenever air enters the system”. Manuals further state “this occurs when any part of the system has been moved or if the fluid level has been allowed to fall so low that air has been drawn into the master cylinder”. Typical repair manuals are the “Ford Pick-ups & Bronco Automotive Repair Manual” and the “Ford Ranger and Bronco II Automotive Repair Manual” published by Haines North America, Inc., 861 Lawrence drive, Newbury Park, Calif. 91320. Chapter eight of these manuals discuss the clutch and driveline including the bleeding of the clutch hydraulic system. This bleeding information (page 8–9) is a part of this background disclosure and is included herein by reference thereto. Illustrations of typical clutch hydraulic control assemblies of this invention are taken from the Ford Repair Manuals and used herein.
The degree of difficulty in bleeding a clutch hydraulic control assembly can be illustrated by an example taken from the Ford Repair Manual. For example, the manual states that the clutch pedal should be depressed to the floor, held for a couple of seconds, released as rapidly as possible and paused for a couple of seconds before repeating this procedure ten times. This is followed by checking the level in the reservoir and the entire operation (ten times) is repeated five or six times before an assistant releases a bleed screw to expel additional air before tightening the bleed screw and releasing the clutch pedal. This procedure is very time consuming and requires a second mechanic to assist in the bleeding operation without any assurance that the procedure will be successful.
A need exists to have a tool and method to assist the auto mechanic in bleeding a clutch hydraulic control assembly. The removal of air from a hydraulic system is critical for the proper operation of the system. The clutch of the vehicle transmission is properly disengaged if the push rod of the slave cylinder is moved a proper distance. With air in the assembly the clutch pedal may be pushed to the floor without disengaging the clutch. Bleeding of the clutch hydraulic control assembly should not be by chance but should provide a more positive and easier method that a single mechanic can use without the aid of an assistant.
Accordingly, an object of the present invention is to provide a bleeder tool apparatus and method that is easy to use and removes air from the clutch hydraulic control assembly of a vehicle.
Another object of the present invention is to provide a clutch bleeder tool assembly that provides a hydraulic pressure to help remove air from the clutch hydraulic control assembly.
A further object of the invention is to provide a clutch bleeder tool assembly that can be easily connected to the clutch hydraulic control assembly and operated by one mechanic.
Yet another object of the present invention is to provide a cost effective clutch bleeder tool assembly that can be used by a vehicle owner to remove air from a clutch hydraulic control assembly.